Originally if a boy or girl is together and their names are Sii and Nua they are meant to be and are really good at gettin along the dirty way.

n. The birth name of somebody who has changed their name. Most commonly attributed to trans people, but can be attributed to any person who has changed their name. (sometimes written as two words: dead name)

v. 1. To call somebody by their deadname.
v. 2. To out somebody's deadname to the public.